You are welcome! 
And yes that seems to be the case if they are going to have access to cannons. Instead of just giving them the [Bombard Cannon] the Haudenosaunee could instead have a unique artillery piece that is similar to the [Light Cannon] from [Age of Empires 3] to a certain extent.
This artillery unit can be named [Portable Cannon] and will be a weaker counterpart of the [Bombard Cannon] in terms of firepower but could be cheaper.
The [Trebuchet] could also be replaced by a unit called the [Flare Archer], which is an idea that I came up with myself. Although the very concept for this unit isn’t exactly new since I took a lot of inspiration from the Aztec [Arrow Knight] in [Age of Empires 3].
Maybe the [Castle] building could instead be renamed to [Stronghold] when playing as any of the Native American civilisations in the game so that it has a less Euro specific name. The same could be done for other civilisations in the game who did not call their own fortified structures to be “Castles”.